There has so far been available, as an in-vehicle audio device, a so-called disc changer in which a desired one is selected from a set of discs for playback.
The disc changer is designed to store a set of discs such as CD (compact disc) together in a magazine case which is entirely installed in the apparatus body. Generally, the body of the disc changer, relatively voluminous, is installed in any other space than the car interior, such as a trunk, while only a part of the disc changer, necessary for controlling the disc changer itself, is installed in the car interior. In this case, the disc cannot be replaced in the car interior, and for the disc replacement, the magazine case has to be removed out of the apparatus body, which is very troublesome.
To avoid such an inconvenience, there has been proposed a disc changer having a body designed to have a predetermined standard size called “1DIN size” and in which a set of six discs is stored together, for example.
The disc changer uses no aforementioned magazine case, and thus the apparatus body, designed to have the predetermined standard size, can be installed in a standardized storage space provided in the in-vehicle center panel. Therefore, the disc replacement can be done in the car interior and thus the disc changer can be used more conveniently.
Referring to FIG. 1, the conventional disc changer will be described below in further detail. The disc changer is generally indicated with a reference 200. As shown, the apparatus body 200 has provided therein a disc compartment 202 in which discs 201 are to be stored. The disc compartment 202 has a stack of trays 203, for example, a set of six trays 203. The apparatus body 200 has a disc insertion/ejection slot 204 provided at the front thereof. A disc 201 inserted through the disc insertion/ejection slot 204 will be placed on the tray 203.
The disc changer 200 includes also a pickup assembly 205 to play a selected one of the discs 201. The pickup assembly 205 includes a pair of chuck levers 206a and 206b to hold the selected disc 201 rotatably while chucking it, and a pickup unit 207 provided on the side, opposite to the disc 201, of the lower one (206a) of the pair of chuck levers.
In the disc changer, a sufficient space to receive the pair of chuck levers 206a and 206b is created above and below the disc 201 selected from those placed on the stacked trays 203. When the disc 201 is chucked by the pair of chuck levers 206a and 206b, it is rotated and the pickup unit 207 reads signals the disc 201 being rotated.
The above disc changer 200 is not advantageous in that when the pickup unit 207 reads signals from the disc 201 chucked between the pair of chuck levers 206a and 206b, the disc 201 will be caused to touch the chuck levers 206a and 206b due to an oscillation or vibration of the vehicle, and thus damaged.
In the conventional disc changer, to protect the disc 201 from being damaged, it has been proposed to attach a cushion member to a portion of each of the chuck levers 206a and 206b, which is likely to be in contact with the disc 201.
However, such a cushion member has to accurately be attached with an adhesive to a portion of each of the chuck levers 206a and 206b, which is likely be in contact with the disc 201, namely, to a limited portion. Since such a portion is limited, highly accurate attachment is very difficult, with the result of the cushion member being out of place.
It is extremely difficult to attain a high accuracy in attaching a cushion member of less than about 0.3 mm, for example, with an adhesive, and such attachment will increase the thickness of the pair of chuck levers 206a and 206b. 
Further, some of the adhesives used for this attachment of the cushion member have not any sufficiently high thermal resistance. Such an adhesive cannot keep the cushion member securely attached on the chuck levers 206a and 206b or the adhesive itself will possibly melt away, when the ambient temperature or temperature of the apparatus is higher.
Also in the aforementioned disc changer, to prevent the disc 201 from being damaged due to contact with the tray 203 during insertion or ejection, it has been proposed to mold the tray 203 itself from a resin, form resin layers over the metallic substrate as the tray 203, or form resin layers on the metallic substrate, which will be in contact with the disc 201, by out-sert molding or bonding.
Since the resin-molded tray is interior in mechanical strength to a tray formed from a metallic substrate, however, it has to be formed thick for a sufficient strength. As a result, the height of the disc changer will be increased.
Also, in case of the tray having resin layers formed over a metallic substrate, a foreign matter is likely to get mixed in the resin going to be applied over the metallic substrate. The foreign matter will scratch the disc 201. Since the resin layer thus formed by coating is extremely thin, additional processing is required to prevent the disc from being damaged by the end face of the metallic substrate.
Also, in case of the tray having a resin layer out-sert molded on a part of the metallic substrate, it is difficult to form a resin layer as thin as 0.1 to 0.2 mm, for example, because of the characteristic of the out-sert molding. To prevent the resin layer from falling off from the tray, any processing has to be made of the substrate side, which will lead to increased costs of manufacturing.
Further, in case of the tray having a resin layer formed on a par of the metallic substrate, it is difficult to attach the thin layer with an adhesive. The attachment is likely to be out of place, and so will be difficult. Also, some of the adhesives used for this attachment of the cushion member have not any sufficiently high thermal resistance. Such an adhesive cannot keep the cushion member securely attached on the chuck levers 206a and 206b or the adhesive itself will possibly melt away, when the ambient temperature or temperature of the apparatus is higher.